Method of splicing unvulcanized rubber tubes for automobile tires and the like



Feb. 9 1926. 1,572,276

' W. L. FAIRCHIL-D METHOD 01 SPLICING UNVULCANIZED RUBBER TUBES FOR AUTOMOBILE TIRES AND THE LIKE Flled Feb 24, 1925 INVENTOR HIS lATTORNEY Patented Feb. 9, 1926. v

UNITED STATES WALTER L. FAIRCHILD, OF NEW YORK, N. Y. I

METHOD on srmome. ouvunoamznn RUBBER TUBES non auroiuonrnn minus AND THE LIKE.

Application filed February 24, 1925.

To all whom it may concern Be it known that I. \VAxrruu L. Fam- (fI-Ilu), a citizen of the l niteil States. and residing at New York, in the count and vState of New York, have invented certain ing together the ends of a tube of unvulcanizcd rubber, and mounting the valve stem therein, preparatory to the vulcanizing operation, whereby the ends of the tube and the seating of the valve stem are united into a substantially homogeneous structure.

Other objects and aims of the invention more or less specific than those referred to above, will be in part obvious and in part pointed out in, the course of the following description of'the steps and the relation of each step to one or more of the others thereof employed in carrying" out my process, and the scope of protection contemplated will be indicated in the appended claims.

In the accompanying drawings, wherein I have shown a. preferred form of embodiment of my invention:

Figure 1 is an elevational view of a scction of unvulcanized rubber tubing.

Figure 2 is a similar view of said tube of unvulcanized rubber, illustrating the first step of the method.

Figure 3 is a similar view, showing the ends of the tubular structure brought together, so that they may be worked together and united by cohesion, preparatoryfio their being subjected to the vulcanizine; process.

Figure 4 a schematic view, showing the manner in which the mandrel which is employed in the preceding step illustrated in Figure 3, is removed from the interior of the tubular structure.

Figure 5 a vertical cross-sectional view taken on line 5 of Figure 3.

lligure (3 is an elevational view of the tubular structure showiug the valve stem inserted through the united portions of the tube.

Figure 7 is a vertical sectional view taker on the line 7-7 of Figure 6.

Serial No. 1 1,066.

l ig ure 8 is a sectional view taken on the line 88 of Figure 6 on an enlarged scale, looking in the direction of the arrows.

Figure 9 is a vertical sectional View of a portion of the tube, showing the manner in which a slit is provided in the end of the tube of unvulcanized rubber, and

Figure 10 is an elevational View showing schematically the manner in which the ends of the unvulcanized tube are united by the employment of the mandrel.

Referring now to the drawings, wherein similar reference characters refer to similar parts throughout the several views thereof, the reference numeral 1 denotes a tube of raw rubber, which has been produced in the usual operation of a tubing machine. It will be understood. of course, that prior to the manual handling of this tube, owing to its tacky condition, the exterior and interior surfaces of the tube have been dusted with powdered soap-stone,:ta le, or the like, so as to prevent the undesirable coherin; together of contacting surfaces.

The first operation performed on the tube, such as illustrated in Figure 1, is to cut a slit 2 in the end 3 thereof, said slit being preferably cut at an angle to the radius of. the tube, as indicated in Figure 9 of the drawings. -When this operation has been accomplished. a valve stem 4 having the usual base or flange is inserted in the slitted end of the tube, as indicated in Figure 2, of the drawings, a mandrel 6 being inserted in the opposite end of said tube, as illustrated in Figure 2. The mandrel 6 is preferably provided with the straight cylindrical surface 7 and the tapered portion 8. The valve stem t is merclv loosely inserted within the end 3 of the tube.

T'Vhen these operations have been coinplet ed, the ends 3 and 9 of the tube are brought together. as illustrated in Figure 3, the end 9 being inserted within the slittcd end 3. The ends of the tube. the contacting" surfaces of which have been cleaned so as to prevent free cohesion, are then thoroughly kneaded, using the mandrel as a base, so that all the contacting surfaces cohere. The parts of the tube, however. in the vicinity of the slit 2, are not kneaded together, said slit being, left open, so that when the kneading operation is completed, the mandrel 4. may be removed through said slit, as indicated in Figure 4. Before the removal of the mandrel,

however, a circular aperture 10 has been out by means of a circular punch in the united ends of thetube, as illustrated in Figure 3. v

The valve stem 4 is then worked forwardly, and the end thereof prdjected outwardly through the aperture 10, so that the flange or base 5 surrounds the aperture 10 within the tubular structure. .The next operation is to provide a base patch 11, having a central aperture, and push this base patch downwardlyover the valve stem i, bringing it in contact with the outer surface of the united ends of the tube. In this connection it may be noted that this base patch is composed of laminated layers of frictioned and unvulcanized rubber, the end surface of said base patch being in a tacky condition, so that the basepatch may be united to the surface of the tube which it overlies by a kneading operation. Assuming the basepatch to have been positioned on the tube as indicated in Figures 6 and 8, the aforementioned kneading operation is accomplished whereby all the contacting parts of the unvulcanized rubber are united by cohesive action.

It will be noted that the valve stem 4: adjacent to the base 5 is provided with a channel 13, and that the aperture 10' cut into the united ends of the tube 13 of smaller diameter than that of the valve stem proper, so that when the tube and base patch 12 are brought into operative relation the edges of their respective apertures closely hug the channelled portion 13 of the valve stem.

The tube is now ready to be subjected to the vulcanizing operation which operation unites all of the cohes'ively united parts into a homogeneous structure surrounding the neck of the valve stem.

The slit 2 will during this operation have been closed and the meeting edges 14 and 15 brought together so that they will be united by the aforesaid kneading operation. Tn this connection it will be seen that the cutting of this slit 2 at an angle the axis of the tube as indicated in Figure 9 facilitates the unity of the edges of the slit.

It will be accordingly seen I have provided a method of uniting the ends of a pneumatic tube formed of unvulcanized rubber, and mountin therein the valve stem which may be carried out man exceedingly simple manner. The operation may also be carried on more expeditiously than have been carried on similar methods as hitherto practiced. I I I As many changes could be made in this construction without departing from the scope of the following claims, it is intended that all matter contained in the above description or shown in the accompanying drawing shall beihter reted as illustrative only and not ind-limiting sense.

Ha-ving thus described my invention, and in what manner the same may be performed,

What I claim as new and desire to secure by Letters Patent is:

1. The herein described method of forum ing a pneumatic tube of unvulcanized rubher which consists of providing a section of said tubing of suitable length, providing a slit in one end of said section, mounting a ,mandrel in the other end of said section,

edges of said slit, mounting an apertured base patch upon said tube so that the aperture thereof surrounds the neck of the valve stem, and then kneading said tube in the vicinity of said valve stem and slit so that cont-acting surfaces of the wall of the tube are united by cohesion.

2. The herein described process of, forming a pneumatic tube, whichconsists of providing a section of unvulcanized rubber tubing, forming a slit in one end of said section,

1nserti ng a mandrel in the otherend thereof, bringing the ends of said tube together with a portion of said slittedpartthereotoverlying the lapping upon the end of said section containing .the mandrel, kneading said tube upon said mandrel to unite by co hesion the overlying or lapped portions of the ends of the tube, cutting an aperture through the said lap ed portions using said mandrel as a, base or the' cutting instrument, removing said mandrel through said slit, inserting a valve stem through said aperture, bringing" together the edges of said slit, mounting an apertured base patch upon the outer wall of said tubular structure so that the aperture of the said base patch surrounds the neck of the valve stem,

and then kneading together ali e]? the con' tacting surfaces of the tube and slit in the vicinity of the valve stem, so that contacting surfaces unite by cohesion preparatory to the vulcanizing operation. I

3. The herein described process of forming a pneumatic tube, which consists of pro viding a section of unvulcani-zed rubber tubing of suitable length, providing a slit in one end of said section, mounting a mandrel in the other end of saidsectiom-inserting a valve stem loosely in tbeslitted end of the section, bringing the ends of said section together so that the slitted end overlies that end of the tube containing the mandrel, kneading the overlapping portions of the tube together using theimandrel as a base, cutting'an aperturethrough the overlapped emme poriions of ihe iube, removing mandrel through said slit; working said valve stem forwaiwily and bringing the end thereof upwardly so that the base of the valve stem surroumxs the aperture interiorly of the tube, bringing the edges of the said slittogether. positioning on apertured base patch upon the outer wall of the overlapped ends of the tube so that the aperture thereof surrounds the neck of ihe voive stem and! then.

by cohesion preparatory tothe vulcanizing operation.

In testimony whereof I aflix my signature WALTER L. mifeomno. 

